Improvement in the manufacture of iron



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Letters Patent No. 90,494, dated May 25, 1869.

IMPROVEMENT IN THE MANUFACTURE OF IRON.

The Schedule referred to in these Letters Patent and making part of the some.

To whom it may conccmt:

Be it known that I, JOHN BURT, of Detroit, in the county of Wayne, and State of Michigan, have invented certain new and useful Improvements in the Manufacture of Iron; and hereby declare the following to be a full, clear, and exact description of the same.

My invention relates to the production, from pig or cast-iron, of what 1 term crude bloom, to be em ployed in the manufacture of iron and steel; and

Its object is to produce a bloom which shall be better. fitted for commercial purposes, and in which the metal shall be more homogeneous than has heretofore been practicable.

To this end, my invention consists in combining, in a closed or open crucible, ofsuitable form, which may or may not be subjected to heat during the operation, melted iron, either taken direct from the blast-furnace, or remelted, with oxides of iron alone, or in combination with carboniziug-agents, said oxide or oxides and carbonizing-ageuts being placed in the bottom of the crucible, and the molten metal run in on top, so that y the former ingredients shall, by reason of diiference in gravity, rise through and permeate the metal, thus bringing it approximately toa homogeneous condition.

In order to eifect as thorough a mixture as possible of the reducing, carbonizing, or-decarbonizing-agents with the metal, my invention further consists in making the crucible in which the operation is carried on, reversible, so that at the proper stage, that is to say, when said agents have partly or wholly passed up through and acted on the metal, the crucible may be turned over, thus reversing the position of the substances contained thcrein, l'n'inging the oxides or other agents again below the mass of metal, through which they are thus again caused to pass, this operation being repeated until the metal has been brought to the proper state.

Further features of my invention will be understood from the following description of the process which I employ.

1 take a closed crucible or mould, having a movable top, or made in sections, so that it may be taken apart to allow the removal of the formed bloom.

Into this crucible I put the proper proportion of pulverized oxide of iron, or oxides and carbons required for the molten metal and then, through a tap or hole in the top of the crucible, I pour in the molten metal, either taken directly from the .blast-tur'iiace, or consisting of remelted pig or cast-iron, until the crucible is filled. The hole may then be closed, if desired, by a plate, which will prevent all escape of metal, while 'ermittin the disen a 'ed ases to ass out.

P i: a o o The moment the metal is poured in, the oxides or oxides and carbons, being of less spccilie gravity, begin to rise through and permeate the mass, mixing intimately with it.

l find, \vheii the oxide is passed only once through the metal, that-sometimes, while the upper part of the mass is brought to nearly the required condition, there is a-stratum in the bottom of the crucible, which, while purified to a certain extent, is not acted upon to the proper degree, and to remedy this defect, as well as to still further improve the quality of the upper portion of the mass, and, in fact, to render the whole mass, as nearly as possible, homogeneous, and of i qual quality. throughout, I mount the crucible on truuuioas, so that at the proper moment, as above specified, it. may be turned over, thus bringing the lower stratum of metal on top, the upper portion of the metal below the said stratum, and the oxides again underneath the whole mass. The latter are thus caused to pass up through the reversed bath of metal, and the operation is carried on in this way until the metal has been brought to the proper condition. \Vhen this takes place, the bloom is allowed to cool, and is then turned out of the mould or crucible.

In this process it will be noticed- First, the metal is in a closed crucible, and is not, subjected to the action of the atmosphere, and there is therefore no oxidation.

Second, the metal should he in a highly-heated condition until the close of the operation, this being essential in order to the perfect mingling of the oxide with it, and it should not be chilled until the bloom is brought to the condition required. 7

In fact, I contemplate heating the crucibles directly during the progress of the operation, either by placing them in a revclberatory furnace, or by other suitable means, or the heat may be maintained by heating the oxides, prior to placing them in the crucible, to any degree below the fusing-point.

In some cases I can tamp the oxides in the bottom of the crucible, before running in the metal, thus preventing it from dying or rising with too great rapidity.

And in case other agents, such as carboniziug-agents, are employed with the oxides, this being determined by the nature and quality of the crude metal, or the quantity of the crude bloom to be produced, I mix them in the proper proportions before placing them in the crucible; as, for instance, charcoal or petroleum may be mixed with the crushed or pulverized oxides; and again, I contemplate moistening the oxide with water, which, when decomposed into its constituent elements by the intense heat of the molten metal, will aid considerably in bringing the metal to the proper condition.

As above specified, the heat in the crucible should be maintained until the bloom is brought to condition. The use oi hydrocarbons is advantageous in this connection, but I can use also nitrate of soda, or vother agent, for intensifying the heat, mixed with the mass in the crucible.

'Ihe bloom, when thus made, is not composed of al- -and saving of time.

Fine wrought or cast-iron scrap, borings, or turnings may be mixed with the oxide, or oxides and carbons,

and the molten metal run in over the whole mass, the

operation being conducted in the manner above ilescribed. I find that this mixture works into'the mass with great facility during the subsequent reheating,

rolling, 850.

It will be noticed that theprocess, as above described, contemplates the employment of a' closed crucible. Yet, as mentioned in the former part of this specification, I can also use an open crucibl'e or mould, the process being essentially the same as before described,excepting, that as the crucible is open, it cannot be reversed. The melted iron should be-"poured or run carfullyover the oxide, 'or other ingredient in the mould, so as not to i'naterially disturb it, and'the liquid I condition of the molten iron should be carefully looked to, so as to maintain it in condition'to, permit the intimate mixture of the reducing or carbonizing-agents.

I In fact, this condition is quite indispensable to the success of the process, whether conducted in an open 'or closed mould. The iron must be kept in a melted state t the close of the operation, and is not built up with the oxides iuasolid mass from the start, as is done by the Ellershausen process, so called.

Havingnow described my invention, and the mannor in which the same is or may be carried into effect, What I claim, and desire to secure by Letters Patent, is-

l 1. The manufacture of :crude bloom, by mixing the molten or cast 'metaland oxidizing or carbonizingagents employed, in a closed or open crucible or mould, substantially as and for the purposes set forth.

2. Maintaining the heat in the crucible during the formation of the crude bloom, by heating the sameexternally, or by mixing suitable heating-agents with the mass within the crucible, substantially as and for the purposes set forth.

3. The employment, in the manufacture of the crude bloom, of a closed reversible crucible or mould, to effect the thorough -mixture of the ingredients placed within it, substantially as set forth.

. 4. The mixture, within aclosed or open crucible, of

"the molten cast-metal, with a mixture of oxides, fine cast or wrought-scrap and carbons, for the purpose of increasing the quantity of the metal in the crude bloom, substantially as herein set forth.

In testimony whereof, I have signed my name to this specification, before two subscribing witnesses.

7 JOHN. BURT. Witnesses M. BAILEY,

Emu. F. BROWN. 

